US8294532B2 - Duplex filter comprised of dielectric cores having at least one wall extending above a top surface thereof for isolating through hole resonators - Google Patents

Duplex filter comprised of dielectric cores having at least one wall extending above a top surface thereof for isolating through hole resonators Download PDF

Info

Publication number
US8294532B2
US8294532B2 US12/683,997 US68399710A US8294532B2 US 8294532 B2 US8294532 B2 US 8294532B2 US 68399710 A US68399710 A US 68399710A US 8294532 B2 US8294532 B2 US 8294532B2
Authority
US
United States
Prior art keywords
top surface
core
wall
holes
extending
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active, expires
Application number
US12/683,997
Other languages
English (en)
Other versions
US20100141352A1 (en
Inventor
Jeffrey J. Nummerdor
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
CTS Corp
Original Assignee
CTS Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US12/316,233 external-priority patent/US8261714B2/en
Application filed by CTS Corp filed Critical CTS Corp
Priority to US12/683,997 priority Critical patent/US8294532B2/en
Publication of US20100141352A1 publication Critical patent/US20100141352A1/en
Assigned to CTS CORPORATION reassignment CTS CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: NUMMERDOR, JEFFREY J.
Priority to US13/654,639 priority patent/US9030272B2/en
Application granted granted Critical
Publication of US8294532B2 publication Critical patent/US8294532B2/en
Active legal-status Critical Current
Adjusted expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
    • H01P1/00—Auxiliary devices
    • H01P1/20—Frequency-selective devices, e.g. filters
    • H01P1/201—Filters for transverse electromagnetic waves
    • H01P1/205—Comb or interdigital filters; Cascaded coaxial cavities
    • H01P1/2056—Comb filters or interdigital filters with metallised resonator holes in a dielectric block
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
    • H01P1/00—Auxiliary devices
    • H01P1/20—Frequency-selective devices, e.g. filters
    • H01P1/201—Filters for transverse electromagnetic waves
    • H01P1/205—Comb or interdigital filters; Cascaded coaxial cavities
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
    • H01P1/00—Auxiliary devices
    • H01P1/20—Frequency-selective devices, e.g. filters
    • H01P1/213—Frequency-selective devices, e.g. filters combining or separating two or more different frequencies
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
    • H01P1/00—Auxiliary devices
    • H01P1/20—Frequency-selective devices, e.g. filters
    • H01P1/213—Frequency-selective devices, e.g. filters combining or separating two or more different frequencies
    • H01P1/2136—Frequency-selective devices, e.g. filters combining or separating two or more different frequencies using comb or interdigital filters; using cascaded coaxial cavities

Definitions

  • This invention relates to dielectric block filters for radio-frequency signals and, in particular, to monoblock duplex filters.
  • Ceramic block filters offer several advantages over lumped component filters.
  • the blocks are relatively easy to manufacture, rugged, and relatively compact.
  • the resonators are formed by typically cylindrical passages, called through-holes, extending through the block from the long narrow side to the opposite long narrow side.
  • the block is substantially plated with a conductive material (i.e. metallized) on all but one of its six (outer) sides and on the inside walls formed by the resonator through-holes.
  • One of the two opposing sides containing through-hole openings is not fully metallized, but instead bears a metallization pattern designed to couple input and output signals through the series of resonators.
  • This patterned side is conventionally labeled the top of the block. In some designs, the pattern may extend to sides of the block, where input/output electrodes are formed.
  • the reactive coupling between adjacent resonators is dictated, at least to some extent, by the physical dimensions of each resonator, by the orientation of each resonator with respect to the other resonators, and by aspects of the top surface metallization pattern. Interactions of the electromagnetic fields within and around the block are complex and difficult to predict.
  • These filters may also be equipped with an external metallic shield attached to and positioned across the open-circuited end of the block in order to cancel parasitic coupling between non-adjacent resonators and to achieve acceptable stopbands.
  • Coupled with the higher frequencies and crowded channels are the customer trends towards the use of the same printed circuit board and filter across the different operating frequencies of different frequency platforms and the consumer market trends towards ever smaller wireless communication devices and longer battery life. Combined, these trends place difficult constraints on the design of wireless components such as filters. Filter designers may not simply add more space-taking resonators (i.e., increase the size of the filter) or allow greater insertion loss in order to provide improved signal rejection.
  • the present invention is directed to a filter which comprises a core with a top surface, a bottom surface, and side surfaces.
  • the core defines a first and second set of spaced-apart through-holes, and each of the through-holes extend through the core from an opening defined in the top surface to an opening defined in the bottom surface.
  • At least first, second, and third posts extend outwardly from the top surface.
  • the filter includes a surface-layer pattern of metallized and unmetallized areas on the core including a first connection area of metallization or electrode located on the top surface and extending onto the first post, a second connection area of metallization or electrode located on the top surface and extending onto the second post, and a third connection area of metallization or antenna located on the top surface and extending onto the third post.
  • the first, second, and third posts define a top rim adapted to be seated against a top surface of a printed circuit board.
  • At least first, second, and third walls extend upwardly from the top surface and the first, second, and third posts are formed on the first, second, and third walls respectively.
  • first and second walls are opposed to each other and the third wall connects the first and second walls and the plurality of walls and the top surface together define a cavity in the filter.
  • respective posts are defined by respective slots formed in the respective walls.
  • another wall extends upwardly from the top surface and separates the openings of the respective first and second set of spaced-apart through-holes.
  • the core is made of first and second blocks which have been coupled together and define the first and second set of spaced-apart through-holes respectively.
  • Each of the first and second blocks includes at least one outer metallized outer surface which defines a central interior layer of metallization when the first and second blocks are coupled together along the respective outer metallized outer surfaces.
  • FIG. 1 is a top side perspective view of the transmit or low band filter or branch of the duplex filter of the present invention
  • FIG. 2 is a top perspective view of the receive or high band filter or branch of the duplex filter of the present invention
  • FIG. 3 is a top perspective view of one embodiment of the duplex filter in accordance with the present invention comprised of the FIG. 1 and FIG. 2 filters coupled together;
  • FIG. 4 is a top perspective view of the duplex filter of FIG. 3 mounted cavity/top side down to a customer's circuit board;
  • FIG. 5 is a graph of signal strength (or loss) versus frequency for the duplex filter of the present invention shown in FIGS. 3 and 4 .
  • FIG. 3 depicts one embodiment of a duplex filter 800 in accordance with the present invention comprised of a transmit or low band simplex signal filter or branch 10 ( FIG. 1 ) and a receive or high band simplex signal filter or branch 400 ( FIG. 2 ) which have been appropriately coupled together in a side-by-side relationship as explained in more detail below.
  • transmit filter 10 of duplex filter 800 ( FIG. 3 ) comprises a generally elongate, parallelepiped or box-shaped rigid block or core 12 comprised of a ceramic dielectric material having a desired dielectric constant.
  • the dielectric material can be a barium or neodymium ceramic with a dielectric constant of about 37 or above.
  • Core 12 defines an outer surface with six generally rectangular sides or surfaces: a top longitudinal surface 14 ; a bottom longitudinal surface 16 ( FIG. 4 ) that is parallel to and diametrically opposed from top surface 14 ; a first side longitudinal surface 18 ; a second longitudinal side surface 20 ( FIG. 4 ) that is parallel to and diametrically opposed from the first side longitudinal surface 18 ; a third transverse side or end surface 22 ; and a fourth transverse side or end surface 24 that is parallel to and diametrically opposed from the third transverse side or end surface 22 .
  • Core 12 additionally defines four generally planar walls 110 , 120 , 130 and 140 that extend upwardly and outwardly away from the respective four outer peripheral edges of the top surface 14 .
  • Walls 110 , 120 , 130 , 140 together define a peripheral top filter rim 200 and walls 110 , 120 , 130 , 140 and top surface 14 together define a cavity 150 in the top of the filter 10 .
  • Longitudinally extending walls 110 and 120 are parallel and diametrically opposed to each other.
  • Transversely extending walls 130 and 140 are parallel and diametrically opposed to each other and are coupled to and generally normal with the walls 110 and 120 .
  • Wall 110 has an outer surface 111 ( FIG. 4 ) and an inner surface 112 .
  • the outer surface 111 is co-extensive and co-planar with side surface 20 ( FIG. 4 ).
  • a central portion 110 C of wall 110 includes an inner surface 112 C which slopes or angles outwardly and downwardly away from the rim 200 into top surface 14 in the direction of opposed wall 120 at approximately a 45 degree angle relative to both the top surface 14 and the wall 110 .
  • Walls 120 , 130 and 140 all define generally vertical outer walls generally co-planar with the respective core side surfaces and generally vertical inner walls that are generally substantially in a relationship that is normal to the horizontal plane defined by top surface 14 .
  • Wall 110 additionally defines a plurality of generally parallel and spaced-apart wall portions.
  • An end wall portion 110 A is defined adjacent and normal to the wall 130 .
  • An upwardly extending isolated ground wall portion or post or finger 1108 is defined adjacent and spaced from the wall portion 110 A.
  • a slot 160 is defined between the end wall portion 110 A and the post 110 B.
  • a central wall portion 110 C is located adjacent but spaced from the post 110 B.
  • a slot 162 is defined between the post 110 B and central wall portion 110 C.
  • An upwardly extending isolated wall portion or post or finger 110 D is located adjacent but spaced from the central wall portion 110 C.
  • a slot 164 is defined between the central wall portion 110 C and the post 110 D.
  • Post 110 D is diametrically opposed to post 110 B and is defined in an end portion of wall 110 adjacent the wall 140 .
  • An end wall portion 110 E is defined between the wall 140 and the post 110 D.
  • Wall portion 110 E is normal to the wall 140 .
  • a slot 166 is defined between the post 110 D and the wall portion 110 E.
  • Inner surface 112 of wall 110 is further separated into several portions including inner vertical portions 112 A and 112 B and inner angled or sloped surface portions 112 C, 112 D and 112 E.
  • Inner surface portion 112 A is located on wall portion 110 A.
  • Inner surface portion 112 B is located on wall portion or post 110 B.
  • Inner surface portion 112 C is located on wall portion 110 C.
  • Inner surface portion 112 D is located on wall portion or post 110 D.
  • Inner surface portion 112 E is located on wall portion 110 E.
  • Wall portions 110 C, 110 D, and 110 E further define generally triangularly-shaped side walls. Specifically, wall portion 110 C defines a side wall 114 D spaced from post 110 B and an opposed side wall 114 E spaced from post 110 D. Post 110 D defines a side wall 114 F spaced from wall portion 110 C and a side wall 114 G spaced from wall portion 110 E. Wall portion 110 E defines a side wall 114 H spaced from post 110 D.
  • Wall 120 has an outer surface 121 and an inner surface (not shown). Outer surface 121 is co-extensive and co-planar with the core side surface 18 and the inner surface (not shown) is normal with the core top surface 14 .
  • Wall 130 has an outer surface 131 and an inner surface 132 .
  • Outer surface 131 is co-extensive and co-planar with the core side surface 24 and inner surface (not shown) is normal with the core top surface 14 .
  • Wall 140 has an outer surface (not shown) and an inner surface 142 .
  • Outer surface (not shown) is co-extensive and co-planar with the core side surface 22 and inner surface 142 is normal with the core top surface 14 .
  • An upwardly extending isolated wall portion or post or finger 300 is defined at a lower left corner of core 12 which bridges the core side surfaces 18 and 24 .
  • the post 300 is spaced from the walls 120 and 130 so as to define a slot 302 between the post 300 and wall 130 and a slot 304 between the post 300 and the wall 120 .
  • Post 300 defines a pair of generally triangularly-shaped side walls 308 which are not covered with metallization and are contiguous with the non-metallized area 44 as described in more detail below.
  • the outside side wall 308 is co-planar with the side core surface 18 and the outside surface 121 of wall 120 .
  • Post 300 has a metallized top rim 312 , a metallized front face 306 which is co-planar with the core end surface 24 and the outside surface 131 of wall 130 , and a metallized inner angled or sloped surface 310 .
  • Simplex transmit signal filter 10 additionally comprises a plurality of resonators 25 defined in part by a plurality of metallized through-holes 30 which are defined in dielectric core 12 and terminate in respective openings in the top and bottom surfaces 14 ( FIG. 1) and 16 ( FIG. 4 ) of the core 12 .
  • Through-holes 30 extend along the length of the block 12 from a point adjacent the core side surface 22 to a point adjacent the opposed core side surface 24 in a spaced-apart, co-linear relationship.
  • Each of the through-holes 30 is defined by an inner cylindrical metallized side-wall surface 32 .
  • Top surface 14 of core 12 additionally defines a surface-layer recessed pattern 40 of respective electrically conductive metallized and insulative unmetallized areas or patterns.
  • a portion of pattern 40 is defined on the top surface 14 of core 12 and thus defines a recessed filter pattern by virtue of its recessed location at the base of cavity 150 in spaced relationship from and with the top rim 200 of core walls 110 , 120 , 130 , and 140 .
  • the metallized areas may be a surface layer of conductive silver-containing material.
  • Recessed pattern 40 also defines a wide area or pattern of metallization that covers the core bottom surface 16 , all of the core side surfaces, and the side wall 32 of respective through-holes 30 and extends contiguously from within resonator through-holes 30 towards both core top surface 14 and core bottom surface 16 and may also be labeled a ground electrode which serves to absorb or prevent transmission of off-band signals.
  • the recessed pattern 40 on core top surface 14 is at least comprised of resonator pads 60 A, 60 B, 60 C, 60 D, 60 E and 60 F which at least partially surround the top openings of respective through-holes 30 .
  • Resonator pads 60 A- 60 F are contiguous or connected with the metallization area that extends through the respective inner surfaces 32 of through-holes 30 and are shaped to have predetermined capacitive couplings to adjacent resonators and other areas of surface-layer metallization.
  • An unmetallized area or pattern 44 surrounds all of the metallized resonator pads 60 A- 60 F; extends over at least portions of the core side surfaces 18 , 20 , and 24 ; onto core top surface slot portions 182 , 183 , 320 and 322 ; and onto core side wall portions 114 E, 114 F, 114 G, 114 H, and outside side wall 308 of the post 300 .
  • Unmetallized area 44 also defines a generally rectangularly-shaped unmetallized area 314 which extends onto a portion of core side surface 24 located below the front face 306 of the post 300 and the slot 302 .
  • Another generally rectangularly-shaped unmetallized area 316 is coupled with the area 314 and extends onto a portion of core side surface 18 located below the outside side wall 308 of post 300 and the slot 304 .
  • a similar generally rectangularly-shaped unmetallized area 317 extends onto a portion of the core side surface 20 located above the post 110 D and slots 164 and 166 .
  • Surface-layer pattern 40 on core top surface 14 additionally defines a pair of isolated conductive metallized signal areas: a transmit input/output signal connection area or electrode 210 ; and an antenna input/output signal connection area or electrode 330 .
  • Input/output signal connection area 210 extends onto a portion of wall 110 and, more specifically, onto the inner surface and top rim portions 112 and 200 of RF signal input/output post 110 D to define, for example, a surface mounting transmit signal conductive connection point or pad or contact as described in more detail below.
  • Connection area of metallization or electrode 210 is located adjacent the wall 140 .
  • Input connection area or electrode 210 includes electrode portions 211 , 212 , 213 and 214 .
  • Electrode portion 211 is located between resonator pads 60 E and 60 F and connects with electrode portion 212 that is located on inner surface portion 112 D of post 110 D.
  • Electrode portion 213 connects with electrode portions 211 and 212 .
  • Electrode portion 214 is located on the top rim portion 200 of post 110 D. Electrode portion 214 connects with the electrode portion (not shown) that is located on the outer surface of the post 110 D. Electrode portion 214 is surrounded on all sides by unmetallized areas.
  • Antenna connection area 330 extends onto post 300 where it serves as an antenna surface mounting conductive connection point or pad or contact or post as described in more detail below.
  • Electrode 330 includes electrode portions 331 , 332 , 333 , 334 and 335 .
  • Electrode portion 332 is located between resonator pads 60 A and 608 and connects with electrode portion 331 .
  • Electrode portion 333 is located on the inner surface portion 310 of post 300 and connects with electrode portion 331 .
  • Electrode portion 334 is located on the top rim portion 200 of post 300 and connects with electrode portion 333 .
  • Electrode portion 335 is located on the outer surface 306 of post 300 and is surrounded on all sides by unmetallized areas.
  • the recessed surface pattern 40 includes metallized areas and unmetallized areas.
  • the metallized areas are spaced apart from one another and are therefore capacitively coupled.
  • the amount of capacitive coupling is roughly related to the size of the metallization areas and the separation distance between adjacent metallized portions as well as the overall core configuration and the dielectric constant of the core dielectric material.
  • surface pattern 40 also creates inductive coupling between the metallized areas.
  • simplex receive signal filter 400 comprises a generally elongate, parallelepiped or box-shaped rigid block or core 412 comprised of a ceramic dielectric material having a desired dielectric constant.
  • the dielectric material can be a barium or neodymium ceramic with a dielectric constant of about 37 or above.
  • Core 412 defines an outer surface with six generally rectangular sides: a core top longitudinal surface 414 ; a core bottom longitudinal surface 416 ( FIG. 4 ) that is parallel to and diametrically opposed from the core top surface 414 ; a first core side longitudinal surface 418 ; a second core side longitudinal surface 420 that is parallel to and diametrically opposed from side surface 418 ; a third transverse core side or end surface 424 ; and a fourth transverse core side or end surface 422 that is parallel to and diametrically opposed from the core end surface 424 .
  • Core 412 additionally defines four generally planar walls 510 , 520 , 530 and 540 that extend upwardly and outwardly away from the respective four outer peripheral edges of the core top surface 414 .
  • Walls 510 , 520 , 530 , and 540 together define a top peripheral rim 600 and the walls 510 , 520 , 530 , 540 and top surface 414 together combine to define a cavity 550 at the top of the filter 400 .
  • Longitudinally extending walls 510 and 520 are parallel and diametrically opposed to each other.
  • Transversely extending walls 530 and 540 are parallel and diametrically opposed to each other and are coupled to, and generally normal to, the walls 510 and 520 .
  • Wall 510 has an outer surface 511 and an inner surface 512 .
  • Outer surface 511 is co-extensive and co-planar with the core side surface 418 while a portion of the inner surface 512 slopes or angles outwardly and downwardly away from the rim 600 into the core top surface 414 in the direction of opposed wall 520 at approximately a 45 degree angle relative to both the core top surface 414 and the wall 510 .
  • Walls 520 , 530 and 540 all define generally vertical outer walls generally co-planar with the respective core side surfaces 420 , 424 , and 422 and generally vertical inner walls that are generally substantially in a relationship that is normal to the horizontal plane defined by the core top surface 414 .
  • Wall 510 additionally defines a plurality of generally parallel and spaced-apart slots 560 , 562 , 564 and 566 .
  • An end wall portion 510 A is defined between the wall 530 and slot 560 .
  • End wall portion 510 A is normal to the wall 530 .
  • An isolated ground wall portion or post or finger 510 B is located adjacent but spaced from the wall portion 510 A and the space therebetween defines the slot 560 .
  • a center wall portion 510 C is located adjacent but spaced from the post 5106 and the space therebetween defines the slot 562 .
  • An isolated wall portion or post or finger 510 D is located adjacent but spaced from the center wall portion 510 C and the space therebetween defines the slot 564 .
  • Post 510 D is diametrically opposed to post 510 B.
  • An end wall portion 510 E is located adjacent but spaced from the post 510 B and the space therebetween defines the slot 566 .
  • Posts 510 B and 510 D extend generally normally outwardly and upwardly away from the core top surface 414 of filter 400 .
  • the inner surface of selected ones of the portions of wall 510 is angled or sloped.
  • An inner angled surface portion 512 C is located on wall portion 510 C.
  • An inner angled surface portion 512 D is located on wall portion or post 510 D.
  • An inner angled surface portion 512 E is located on wall portion 510 E.
  • Wall portions 510 C, 510 D, and 510 E further define generally triangularly-shaped side walls. Specifically, wall portion 510 C defines a side wall 514 D adjacent the post 510 B and an opposed side wall (not shown) adjacent the post 510 D. Post 510 D defines a side wall 514 F adjacent the wall portion 510 C and a side wall 514 G adjacent the end wall portion 510 E. Wall portion 510 E defines a side wall 514 H adjacent the post 510 D.
  • Wall 520 has an outer surface (not shown) and an inner surface 522 .
  • the outer surface (not shown) is co-extensive and co-planar with the core side surface 420 and the inner surface 522 is normal with the core top surface 414 .
  • Wall 530 has an outer surface 531 and an inner surface (not shown). Outer surface 531 is co-extensive and co-planar with the core side surface 424 and the inner surface (not shown) is normal with the core top surface 414 .
  • Wall 540 has an outer surface (not shown) and an inner surface 542 .
  • the outer surface (not shown) is co-extensive and co-planar with the core side surface 422 and the inner surface 542 is normal with the core top surface 414 .
  • An isolated wall portion or post or finger 700 is defined at the upper left corner of core 412 in a relationship adjacent and spaced from respective walls 520 and 530 .
  • the space between post 700 and wall 530 defines a slot 702 .
  • the space between the post 700 and the wall 520 defines a slot 704 .
  • Post 700 defines a pair of generally triangularly-shaped side walls 709 which are not covered with metallization and are contiguous with non-metallized area 444 on the core top surface 414 as described in more detail below.
  • Post 700 has a metallized top rim 712 , a metallized front face 706 which is co-planar with the core side surface 424 and the outer surface 531 of wall 530 , and a metallized inner angled or sloped surface 710 .
  • Post 700 extends generally normally upwardly and outwardly from the top filter surface 414 .
  • the outside wall 709 of post 700 is co-planar with the core side surface 420 and the outer surface (not shown) of the wall 520 .
  • Receive filter 400 has a plurality of resonators 425 defined in part by a plurality of through-holes 430 ( FIGS. 3 and 4 ) which are defined in dielectric core 412 .
  • Through-holes 430 extend from and terminate in respective openings defined in the top and bottom core surfaces 414 and 416 respectively.
  • Through-holes 430 extend along the longitudinal axis of block 412 in a spaced-apart and co-linear relationship.
  • Each of through-holes 430 is defined by an inner cylindrical metallized side-wall surface 432 .
  • Top surface 414 of core 412 additionally defines a surface-layer recessed pattern 440 of electrically conductive metallized and insulative unmetallized areas or patterns.
  • a portion of pattern 440 is defined on the top surface 414 of core 412 and thus defines a recessed filter pattern by virtue of its recessed location at the base of cavity 550 in spaced relationship from and with the top rim 600 of walls 510 , 520 , 530 , and 540 .
  • the metallized areas may be a surface layer of conductive silver-containing material.
  • Recessed pattern 440 also defines a wide area or pattern or portion of metallization that covers the top, bottom, and side core surfaces 414 , 416 , 418 , 420 , 422 , and 424 , and the inner walls 432 of through-holes 430 and extends contiguously from within resonator through-holes 430 towards both top surface 414 and bottom surface 416 and may also be labeled a ground electrode and serves to absorb or prevent transmission of off-band signals.
  • the recessed pattern 440 on the core top surface 414 comprises a plurality of resonator pads 460 A, 4606 , 460 C, 460 D, 460 E and 460 F which at least partially surround the respective openings of through-holes 430 defined on the core top surface 414 .
  • Resonator pads 460 A- 460 F are contiguous or connected with the metallization area that extends through the respective inner surfaces 432 of through-holes 430 and are shaped to have predetermined capacitive couplings to adjacent resonators and other areas of surface-layer metallization.
  • An unmetallized area or pattern 444 extends over portions of the core top surface 414 and at least portions of the core side surfaces 418 , 420 , and 424 .
  • Unmetallized area 444 on the core top surface 414 surrounds all of the metallized resonator pads 460 A- 460 F.
  • Unmetallized area 444 also extends onto and covers at least top surface slot portions 582 , 583 , 720 and 722 and side wall portions 514 E, 514 F, 514 G, 514 H, and 709 .
  • Unmetallized area 444 also defines a generally rectangularly-shaped unmetallized area 714 which extends onto a portion of core side surface 424 located below the front face 706 of post 700 and the slot 702 .
  • Another generally rectangularly-shaped unmetallized area (not shown) is coupled to the unmetallized area 714 and extends onto a portion of the core side surface 420 located below the outside side face (not shown) of the post 700 and the slot 704 .
  • a similar generally rectangularly-shaped unmetallized area 448 extends onto a portion of the core side surface 418 located below the front face of the post 510 D and the slots 564 and 566 .
  • Surface-layer pattern 440 on the core top surface 414 additionally defines a pair of isolated conductive metallized connection areas including a receive signal input/output connection area or electrode 610 and an antenna input/output signal connection area or electrode 730 .
  • Receive signal connection area 610 extends onto a portion of wall 510 and side surface 418 and, more specifically, onto the inner surface and rim portions 512 D and 600 respectively of post 510 D to define a surface mounting receive signal conductive connection point or pad or contact or post as described in more detail below.
  • Electrode 610 is located on top surface 414 adjacent wall 540 .
  • Connection area or electrode 610 includes electrode portions 611 , 612 , 614 and 615 .
  • Electrode portion 611 is located between resonator pads 460 E and 460 F and connects with electrode portion 612 that is located on the inner surface portion 512 D of post 510 D and connects with electrode portion 611 .
  • Electrode portion 614 is located on the rim 600 of post 510 D and connects with electrode portion 612 .
  • Electrode portion 615 is located on the outside face of the post 510 D and connects with electrode portion 614 and is surrounded on all sides by unmetallized areas.
  • Antenna connection area or electrode 730 extends onto the post 700 to define a surface mounting conductive antenna connection point or pad or contact or post as described in more detail below.
  • Antenna connection area of metallization or electrode 730 is generally L-shaped and is located on the core top surface 414 adjacent the wall 530 .
  • Connection area or electrode 730 includes electrode portions 731 , 732 , 733 , 734 and 735 .
  • Electrode portion 732 is located between resonator pads 460 A and 460 B and connects with electrode portion 731 .
  • Electrode portion 733 is located on the inner surface portion 710 of post 700 and connects with electrode portion 731 .
  • Electrode portion 734 is located on the top rim portion 600 of post 700 and connects with electrode portion 733 .
  • Electrode portion 735 is located on the outer surface 706 of post 700 and connects with electrode portion 734 .
  • Electrode portion 735 is surrounded on all sides by unmetallized areas.
  • the recessed surface pattern 440 includes metallized areas and unmetallized areas.
  • the metallized areas are spaced apart from one another and are therefore capacitively coupled.
  • the amount of capacitive coupling is roughly related to the size of the metallization areas and the separation distance between adjacent metallized portions as well as the overall core configuration and the dielectric constant of the core dielectric material.
  • surface pattern 440 creates inductive coupling between the metallized areas.
  • low band or transmit signal simplex filter 10 is joined or coupled to high band or receive signal simplex filter 400 to form and define one embodiment of the duplex filter 800 in accordance with the present invention.
  • Filters 10 and 400 can be joined by a wide variety of methods. For example, because the outer faces of the side longitudinal core surfaces 18 and 420 of respective filters 10 and 400 are covered with metallization, filters 10 and 400 and, more specifically, the side surfaces 18 and 420 and respective walls 120 and 520 thereof may be placed in a side-by-side coupling and abutting relationship and then the filters 10 and 400 can be heated in a furnace causing the metallization on the outer face of side wall 18 of filter 10 and the metallization on the outer face of side wall 420 of filter 400 to sinter and fuse together to form a unitary center metallized interior filter wall 805 which forms and defines a ground plane extending longitudinally along and through the center of the duplex filter 800 between the respective first and second sets of through-holes 830 A and 830 B to advantageously electrically separate and isolate the same. Filters 10 and 400 may also be joined together using conductive epoxies, solders or mechanical joining techniques.
  • Duplex filter 800 being, in one embodiment, composed of the combination of the individual and separate simplex filters 10 and 400 , thus comprises a generally elongate parallelepiped or box-shaped rigid block or core 812 defined by the cores 12 and 412 of respective filters 10 and 400 .
  • Core 812 defines an outer surface with six generally rectangular sides or surfaces: a top longitudinal surface 814 defined by the joined top longitudinal surfaces 14 and 414 of respective filters 10 and 400 ; a bottom longitudinal surface 816 ( FIG. 4 ) which is defined by the joined bottom longitudinal surfaces 16 and 416 as shown in FIG.
  • Core 812 additionally defines four generally planar walls that extend upwardly and outwardly away from the respective four outer peripheral edges of the top surface 814 : longitudinal wall 810 which is defined by the wall 110 of filter 10 ; longitudinal wall 820 which is opposed to wall 810 and is defined by the wall 510 of filter 400 ; transverse side wall 830 which is defined by the joined walls 130 and 530 of respective filters 10 and 400 ; and transverse side wall 840 which is opposed to the wall 830 and is defined by the joined walls 140 and 540 of respective filters 10 and 400 .
  • Walls 810 , 820 , 830 , and 840 together define a top circumferential rim 1000 ; and walls 810 , 820 , 830 , and 840 and the core top surface 814 together define a top filter cavity 850 .
  • Walls 810 and 820 are parallel and diametrically opposed to each other.
  • Walls 830 and 840 are parallel and diametrically opposed to each other and are coupled to and generally normal to the walls 810 and 820 .
  • Longitudinal wall 810 defines a pair of spaced-apart, isolated posts or fingers 1010 B and 1010 D defined by and corresponding in location, structure, and function to the posts or fingers 110 B and 110 D respectively of filter 10 , the description of which is incorporated herein by reference.
  • Post 10108 is located adjacent wall 830 while post 1010 D is located adjacent opposed wall 840 .
  • Opposed longitudinal wall 820 defines a pair of spaced-apart, isolated posts or fingers 15106 and 1510 D defined by and corresponding in location, structure, and function to the posts or fingers 510 B and 510 D respectively of filter 400 , the description of which is incorporated herein by reference.
  • Post 1510 B is located adjacent transverse wall 830 and is diametrically opposed to the post 1010 B.
  • Post 1510 D is located adjacent transverse wall 840 and is diametrically opposed to post 1010 D.
  • Transverse side wall 830 defines an isolated generally centrally located post or finger 1210 which is defined by the coupling together of posts or fingers 300 and 700 of filters 10 and 400 respectively and, more specifically, by the coupling together of the respective outside faces thereof into an abutting relationship.
  • Filter 800 further comprises a central interior longitudinal wall 842 which is defined by the joined walls 120 and 520 of respective filters 10 and 400 and extends in a longitudinal direction through the center of filter 800 from the wall 840 and terminates in an end wall 806 spaced from the opposite wall 830 .
  • Wall 842 extends upwardly and outwardly away from the core top surface 814 of filter 800 in a relationship parallel to and spaced from the walls 810 and 820 .
  • Wall 842 splits, divides, and isolates the filter top surface 814 and cavity 850 into respective generally rectangularly-shaped upper and lower, generally parallel and adjoining transmit and receive filter sections or cavities 852 and 854 respectively.
  • Cavity or section 852 is defined between the respective filter walls 810 and 842 while cavity or section 854 is defined between the respective filter walls 820 and 842 .
  • Section 852 includes a plurality of resonators 825 A defined in part by a plurality of resonator through-holes 830 A and a pattern 840 A of electrically conductive metallized and insulative unmetallized areas or patterns on the core top surface 814 defined by and corresponding in location, structure, and function to the resonators 25 , through-holes 30 , and pattern 40 respectively of filter 10 , the description of which is thus incorporated herein by reference.
  • Through-holes 830 A extend longitudinally along the core top surface 814 of the block/core 812 in spaced-apart and parallel relationship above and parallel to the central interior wall 842 .
  • Each of the through-holes 830 A extends through the core 812 and terminates in respective openings defined in the respective top and bottom surfaces 814 and 816 of the core 812 .
  • the pattern 840 A, post 1010 D, and post 1210 of filter 800 includes respective strips of conductive material 1211 , 1212 , 1214 , 1330 , 1333 , and 1312 defined by and corresponding in location, structure, and function to the respective strips of conductive material 211 , 212 , 214 , 330 , 333 , and 312 of pattern 40 , post 110 D, and post 300 of filter 10 , the description of which is thus incorporated herein by reference.
  • Section 854 includes a plurality of resonators 825 B defined in part by a plurality of resonator through-holes 8306 which are diametrically opposed and parallel to resonator through-holes 830 A and a pattern 840 B of electrically conductive metallized and insulative unmetallized areas or patterns on the top surface 814 defined by and corresponding in location, structure, and function to the resonators 425 , through-holes 430 , and pattern 440 respectively of filter 400 , the description of which is incorporated herein by reference.
  • Through-holes 830 B extend longitudinally along the block/core 812 in a spaced-apart and parallel relationship below and parallel to central interior wall 842 and the through-holes 830 A. Each of the through-holes 830 B extend through the core 812 and terminate in respective openings defined in the respective top and bottom surfaces 814 and 816 of core 812 .
  • the pattern 840 B, post 1510 D, and post 1210 of filter 800 include respective strips 1611 , 1612 , 1614 , 1730 , 1333 , and 1334 of conductive material defined by and corresponding in location, structure, and function to the respective strips of conductive material 611 , 612 , 614 , 730 , 733 , and 734 of pattern 440 , post 510 D, and post 700 respectively of filter 400 , the description of which is thus incorporated herein by reference.
  • the patterns 840 A and 840 B additionally include a layer of metallization which covers the exterior filter surfaces 818 , 820 , 822 , and 824 ; the exterior, interior, and rim of each of the walls 810 , 820 , 830 , 840 , and 842 ; and the interior of each of the resonator through-holes 830 A and 830 B with the exception of the unmetallized regions or areas 1448 , 1714 , and 1715 on the respective core side surfaces 818 , 824 , and 820 .
  • the unmetallized regions 1448 , 1714 , and 1715 are located below the posts 1510 D, 1210 , and 1010 D respectively.
  • the transmit signal connection finger/post/pad/electrode 1010 D is located on the longitudinal wall 810 of filter 800 ; the receive signal connection finger/post/pad/electrode 1510 D is located on the opposite longitudinal wall 820 of filter 800 in a relationship diametrically opposed to the pad 1010 D; and antenna connection finger/post/pad/electrode 1210 is located on the transverse wall 830 which couples the walls 810 and 820 .
  • central interior wall 842 isolates and separates the respective transmit and receive filter sections 852 and 854 , the respective top surface metallization patterns 840 A and 840 B, and further that the respective through-holes 825 A and 825 B.
  • circuit board 900 is a printed circuit board having a top surface 902 , a bottom surface (not shown), and a plurality of side surfaces 903 , 904 , 905 , and 906 .
  • Circuit board 900 has a board height BH that is measured along side 906 between the PCB top surface 902 and the bottom surface (not shown).
  • Circuit board 900 additionally includes plated through-holes 925 that form an electrical connection between the PCB top and bottom surfaces.
  • Several circuit lines 910 and connection pads 912 can be located on top surface 902 and connected with terminals 914 .
  • Circuit lines 910 , connection pads 912 , and terminals 914 are formed from a metal such as copper. Terminals 914 connect duplex filter 800 to an external electrical circuit (not shown).
  • Duplex filter 800 is mounted to the PCB 900 in a top side down relationship wherein the core top surface 814 is located opposite, parallel to, and spaced from the top surface 902 of PCB 900 and the rim 1000 (as shown in FIG. 3 ) defined by the walls 810 , 820 , 830 , 840 , and 842 of filter 800 is seated on and soldered to the top surface 902 of PCB 900 .
  • the cavity 850 defined by the filter 800 is partially sealed to define an enclosure defined by the top surface 814 , the board surface 902 , and the walls 810 , 820 , 830 , 840 , and 842 .
  • the generally vertical elongated through-holes 830 A and 830 B in duplex filter 800 are defined and oriented in a relationship generally substantially perpendicular to the PCB 900 wherein the openings of the respective through-holes 825 A and 825 B face, and are spaced from, the board top surface 902 .
  • the antenna connection post or pad or electrode 1210 and, more specifically, the metallized rim portions 1312 and 1334 thereof on the rim 1000 are seated on and coupled to one of the metallized connection pads 912 of PCB 900 by solder 920 .
  • transmit signal post or pad 1010 D and, more specifically, the metallized rim portion 1214 is seated on and coupled to another one of the connection pads 912 on the board 900 by solder 920 .
  • receive signal post or pad 1510 D and, more specifically, the metallized rim portion 1614 thereof is likewise seated on and coupled to yet another connection pad 912 on the board top surface 902 .
  • the connection pads 912 in turn are coupled to the respective circuit lines 910 .
  • the location of the transmission/input and receive/output connection pads 1010 D and 1510 D on opposite longitudinal sides of the filter 800 advantageously reduces interference and cross-talk and further allows the respective transmission/input and receive/output circuit lines 910 to also be located on opposite longitudinal sides 903 and 906 of the board 900 to create better isolation and reduce interference between the respective circuit lines.
  • Circuit board 900 also has a generally rectangular-shaped ground ring or line 930 disposed on the top surface 902 that can be formed from copper and on which the rim of the respective electrodes and filter walls are attached by solder 935 (only a portion of which is shown in FIG. 4 ).
  • solders 920 and 935 are first screened onto ground ring 930 and connection pads 912 respectively.
  • duplex filter 800 is placed on top surface 902 such that electrode portions 1010 D and 1210 are aligned with connection pads 912 .
  • Circuit board 900 and duplex filter 800 are then placed in a reflow oven to melt and reflow solders 920 and 935 .
  • the attachment of the rim 1000 (as shown in FIG. 3 ) of the respective walls 810 , 820 , 830 , 840 , and 842 to the ground ring 930 forms an electrical path for the grounding of the majority of the outer surface of duplex filter 800 .
  • duplex filter 800 has a length L, a width W, a height H and a resonator length RL that is equal to H.
  • the design of the duplex filter 800 may require that the resonator length (RL) be less than or shorter than the board height (BH).
  • the filter can become unstable at higher frequencies when attached to the circuit board. Additional electromagnetic fields can be created that interfere with and reduce the attenuation of the filter. These additional electromagnetic fields can also reduce the attenuation and sharpness of the attenuation at the filter poles also known as zero points.
  • duplex filter 800 of the present invention with recessed top surface patterns 840 A and 840 B on surface 814 (as all shown in FIG. 3 ) facing and opposite the board 900 provides improved grounding and off band signal absorption; confines the electromagnetic fields within cavity 850 (as shown in FIG. 3 ); and prevents external electromagnetic fields outside of cavity 850 (as shown in FIG. 3 ) from causing noise and interference such that the attenuation and zero points of the filter are improved.
  • the present invention allows the same footprint (length L and width W) to be used across multiple frequency bands.
  • Prior art filters typically require a size or footprint that would either need to increase or decrease depending upon the desired frequency to be filtered.
  • Filter 800 can have the same overall footprint and still be used at various frequencies.
  • filter 800 tends to self align with the ground ring 930 on the PCB 900 .
  • Filter 800 exhibits improved self alignment because the surface tension of the liquid solder 935 during reflow is distributed equally around the rims between ground ring 930 and the rims providing self-centering of the core 812 .
  • duplex filter 800 also eliminates the need for a separate external metal shield or other shielding as currently used to reduce spurious electromagnetic interference incurred, as the walls 810 , 820 , 830 , 840 , and 842 and board 900 provide the shielding. Shielding could still be added, if needed or desired, to filter 800 for a specific application.
  • the present invention also provides improved grounding and confines the electrical fields within cavity 850 to create a filter 800 which exhibits steeper attenuation.
  • isolation is also improved between the metallization patterns and resonator pads in the respective transmit and receive sections of the filter 800 , thus allowing better harmonic suppression over conventional filters.
  • This present invention also further allows for the placement of input, output and antenna electrodes along any edge or wall of the filter 800 .
  • the antenna electrode can be placed on the same side wall as either the transmit/input or receive/output electrodes or pads of the filter. In prior art surface mount filters, all of the electrodes are required to be on the same surface plane of the dielectric block.
  • Recessed patterns 840 A and 840 B still further create a resonant circuit that includes a capacitance and an inductance in series connected to ground.
  • the shape of patterns 840 A and 840 B determines the overall capacitance and inductance values.
  • the capacitance and inductance values are designed to form a resonant circuit that suppresses the frequency response at frequencies outside the passband including various harmonic frequencies at integer intervals of the passband.
  • cavity 850 is formed adjacent top surface 814 , it is noted that the cavity and corresponding walls defining the same may be formed on any one or more of any of the other surfaces of the filter 800 .
  • cavity 850 may only cover a portion of a surface or side of core 812 .
  • cavity 850 may only encompass ten (10%) percent of the area of top surface 814 .
  • multiple cavities may be located or formed on the same side or surface of core 812 by respective additional wall(s).
  • the present invention still further advantageously allows a duplex filter 800 to be formed simply by coupling together respective standard and simplex filters, thus simplifying the manufacturing process and reducing cost.
  • a duplex filter 800 having a length L of 16.17 mm., a height H of 5.1 mm., and a width W of 9.04 mm. was evaluated by computer simulation using microwave office computer simulation software. Simulated filter performance parameters are listed in TABLE 1, below.
  • FIG. 5 is a graph of signal strength (or loss) in dB versus frequency in MHz demonstrating the specific simulated performance of duplex filter 800 in accordance with the present invention which shows that: the low passband or transmit passband is between 880 and 915 MHz and between ⁇ 0.49395 dB and ⁇ 1.201 dB respectively; the high passband or receive passband is between 925 MHz and 960 MHz and between ⁇ 1.2132 dB and ⁇ 1.0586 dB respectively; duplex filter 800 has a peak isolation (S 23 ) between the receive and transmit ports of ⁇ 35.688 dB at ⁇ 918.27 MHz which is an improvement over prior art duplex filters; duplex filter 800 has an S 12 value of ⁇ 45.004 dB at the end of the transmit passband at 915 MHz; and an S 13 value of ⁇ 59.337 dB at the end of the receive passband at 925 MHz.
  • S 23 peak isolation
  • the present invention can be applied to an RF signal filter operating at a variety of frequencies. Suitable applications include, but are not limited to, cellular telephones, cellular telephone base stations, and subscriber units. Other possible higher frequency applications include other telecommunication devices such as satellite communications, Global Positioning Satellites (GPS), or other microwave applications.
  • GPS Global Positioning Satellites

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Control Of Motors That Do Not Use Commutators (AREA)
US12/683,997 2008-12-09 2010-01-07 Duplex filter comprised of dielectric cores having at least one wall extending above a top surface thereof for isolating through hole resonators Active 2029-08-17 US8294532B2 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US12/683,997 US8294532B2 (en) 2008-12-09 2010-01-07 Duplex filter comprised of dielectric cores having at least one wall extending above a top surface thereof for isolating through hole resonators
US13/654,639 US9030272B2 (en) 2010-01-07 2012-10-18 Duplex filter with recessed top pattern and cavity

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US12/316,233 US8261714B2 (en) 2007-12-10 2008-12-09 RF monoblock filter with outwardly extending wall to define a cavity surrounding a top surface of the filter
US20459409P 2009-01-08 2009-01-08
US12/683,997 US8294532B2 (en) 2008-12-09 2010-01-07 Duplex filter comprised of dielectric cores having at least one wall extending above a top surface thereof for isolating through hole resonators

Related Parent Applications (2)

Application Number Title Priority Date Filing Date
US12/316,233 Continuation-In-Part US8261714B2 (en) 2007-12-10 2008-12-09 RF monoblock filter with outwardly extending wall to define a cavity surrounding a top surface of the filter
US13/604,893 Continuation-In-Part US9030275B2 (en) 2008-12-09 2012-09-06 RF monoblock filter with recessed top pattern and cavity providing improved attenuation

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US13/654,639 Continuation-In-Part US9030272B2 (en) 2010-01-07 2012-10-18 Duplex filter with recessed top pattern and cavity

Publications (2)

Publication Number Publication Date
US20100141352A1 US20100141352A1 (en) 2010-06-10
US8294532B2 true US8294532B2 (en) 2012-10-23

Family

ID=42200924

Family Applications (1)

Application Number Title Priority Date Filing Date
US12/683,997 Active 2029-08-17 US8294532B2 (en) 2008-12-09 2010-01-07 Duplex filter comprised of dielectric cores having at least one wall extending above a top surface thereof for isolating through hole resonators

Country Status (8)

Country Link
US (1) US8294532B2 (de)
JP (1) JP2012514954A (de)
KR (1) KR20110102925A (de)
CN (2) CN202308233U (de)
CA (1) CA2749145A1 (de)
DE (1) DE112010000694T5 (de)
GB (1) GB2479108A (de)
WO (1) WO2010080929A1 (de)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130038404A1 (en) * 2010-01-07 2013-02-14 Jeffrey J. Nummerdor Duplex Filter with Recessed Top Pattern and Cavity
RU2636404C2 (ru) * 2016-02-24 2017-11-23 Акционерное Общество "Специальное Конструкторско-Технологическое Бюро По Релейной Технике" (Ао "Сктб Рт") Двухполосный керамический фильтр
US10333191B2 (en) 2016-09-23 2019-06-25 Cts Corporation Ceramic block RF filter having a first plurality of through-hole resonators and a second plurality of through-holes for blocking RF signal coupling
US10587024B2 (en) 2016-10-21 2020-03-10 LGS Innovations LLC Hermetic sealing of ceramic filters
US10587025B2 (en) 2016-11-08 2020-03-10 LGS Innovations LLC Ceramic filter with window coupling
US11433468B2 (en) 2016-09-30 2022-09-06 General Electric Company Electrode for an electro-erosion process and an associated method thereof

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9030275B2 (en) * 2008-12-09 2015-05-12 Cts Corporation RF monoblock filter with recessed top pattern and cavity providing improved attenuation
JP5703917B2 (ja) * 2011-04-08 2015-04-22 宇部興産株式会社 誘電体共振部品
CN104821422A (zh) * 2015-05-12 2015-08-05 庄昆杰 一种低损耗高隔离小型化双宽带合路分路滤波器
GB2558376A (en) * 2016-11-09 2018-07-11 Isotek Microwave Ltd A ceramic dual mode microwave resonant filter and a multiplexer including such a filter
CN108172956B (zh) * 2017-11-16 2019-09-20 上海华为技术有限公司 一种微波合路器
KR102495987B1 (ko) * 2021-04-28 2023-02-06 서울시립대학교 산학협력단 단일 소체 세라믹 웨이브가이드 듀플렉서

Citations (41)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS614303A (ja) 1984-06-19 1986-01-10 Nec Corp 誘電体帯域通過フイルタ
JPS61258502A (ja) 1985-05-10 1986-11-15 Murata Mfg Co Ltd マイクロ波フイルタ
US4673902A (en) 1983-11-25 1987-06-16 Murata Manufacturing Co., Ltd. Dielectric material coaxial resonator filter directly mountable on a circuit board
US4737746A (en) 1985-10-18 1988-04-12 Alps Electric Co., Ltd. Dielectric filter
US4837534A (en) 1988-01-29 1989-06-06 Motorola, Inc. Ceramic block filter with bidirectional tuning
US4937542A (en) 1988-11-16 1990-06-26 Alps Electric Co., Ltd. Dielectric filter
US5079528A (en) 1989-06-21 1992-01-07 Murata Manufacturing Co. Ltd. Dielectric filter
JPH04242301A (ja) 1991-01-17 1992-08-31 Matsushita Electric Ind Co Ltd 誘電体フィルタ
US5144269A (en) 1990-03-20 1992-09-01 Sanyo Electric Co., Ltd. Dielectric filter having external connection formed on dielectric substrate
US5177458A (en) 1991-07-31 1993-01-05 Motorola, Inc. Dielectric filter construction having notched mounting surface
US5191305A (en) * 1991-07-02 1993-03-02 Interstate Electronics Corporation Multiple bandpass filter
US5208566A (en) 1992-01-21 1993-05-04 Motorola, Inc. Dielectric filter having adjacently-positioned resonators of dissimilar cross-sectional dimensions and notched side surface
US5214398A (en) 1990-10-31 1993-05-25 Ube Industries, Ltd. Dielectric filter coupling structure having a compact terminal arrangement
JPH05167308A (ja) 1991-12-11 1993-07-02 Fuji Elelctrochem Co Ltd 誘電体フィルタ
US5227747A (en) 1989-06-15 1993-07-13 Oki Electric Industry Co., Ltd. Dielectric filter having coupling amount adjusting patterns
JPH05275905A (ja) 1992-03-25 1993-10-22 Oki Electric Ind Co Ltd 分波器の実装構造
JPH06216607A (ja) 1993-01-18 1994-08-05 Ube Ind Ltd 誘電体フィルタ及びその製造方法
US5345202A (en) 1991-03-25 1994-09-06 Sanyo Electric Co., Ltd. Dielectric filter comprising a plurality of coaxial resonators of different lengths all having the same resonant frequency
WO1995030250A1 (en) 1994-04-29 1995-11-09 Motorola Inc. An improved ceramic duplex filter
US5486799A (en) 1992-05-08 1996-01-23 Oki Electric Industry Co., Ltd. Strip line filter and duplexer filter using the same
US5563561A (en) 1994-02-17 1996-10-08 Murata Manufacturing Co., Ltd. Dielectric block apparatus having two opposing coaxial resonators separated by an electrode free region
US5572175A (en) 1992-09-07 1996-11-05 Murata Manufacturing Co., Ltd. Coaxial dielectric resonator apparatus having a plurality of side recesses located on a mount substrate
US5602518A (en) 1995-03-24 1997-02-11 Motorola, Inc. Ceramic filter with channeled features to control magnetic coupling
US5686873A (en) * 1993-11-18 1997-11-11 Murata Manufacturing Co., Ltd. Antenna duplexer having transmit and receive portion formed in a single dielectric block
US5731751A (en) 1996-02-28 1998-03-24 Motorola Inc. Ceramic waveguide filter with stacked resonators having capacitive metallized receptacles
US5783978A (en) 1995-06-21 1998-07-21 Matsushita Electric Industrial Co., Ltd. Band rejection filter having a plurality of dielectric resonator with cutout portions having electrodes therein
US5793267A (en) 1996-03-07 1998-08-11 Murata Manufacturing Co., Ltd. Dielectric block filter having first and second resonator arrays coupled together
EP0865094A2 (de) 1997-03-14 1998-09-16 Taiyo Yuden Co., Ltd. Wellenfilter mit zwei oder mehr dielektrischen Koaxialresonatoren in Juxtaposition
US5959511A (en) 1998-04-02 1999-09-28 Cts Corporation Ceramic filter with recessed shield
EP0951089A2 (de) 1998-04-17 1999-10-20 Murata Manufacturing Co., Ltd. Dielektrisches Filter, dielektrischer Duplexer, Montierungsstruktur und Kommunikationsvorrichtung
US6023207A (en) 1996-02-09 2000-02-08 Ngk Spark Plug Co., Ltd. Dielectric filter and method for adjusting resonance frequency of the same
US6052040A (en) 1997-03-03 2000-04-18 Ngk Spark Plug Co., Ltd. Dielectric duplexer with different capacitive coupling between antenna pad and transmitting and receiving sections
US6236288B1 (en) 1997-03-31 2001-05-22 Murata Manufacturing Co., Ltd. Dielectric filter having at least one stepped resonator hole with a recessed or protruding portion, the stepped resonator hole extending from a mounting surface
US6313797B1 (en) 1998-10-22 2001-11-06 Murata Manufacturing Co., Ltd. Dielectric antenna including filter, dielectric antenna including duplexer, and radio apparatus
US20010052832A1 (en) 1999-09-17 2001-12-20 Tdk Corporation Dielectric filter, and method of manufacturing the same
US20020109562A1 (en) 2001-02-15 2002-08-15 Murata Manufacturing Co., Ltd. Dielectric filter, dielectric duplexer, and communication device
US6498542B1 (en) 1999-02-03 2002-12-24 Murata Manufacturing Co., Ltd. Dielectric resonant device, dielectric filter, dielectric duplexer, communication apparatus including the same, and method for forming input-output electrode of the dielectric resonant device
US20030151468A1 (en) 2002-02-14 2003-08-14 Reddy Vangala Reduced length metallized ceramic duplexer
US6737943B2 (en) 2001-07-25 2004-05-18 Tdk Corporation Dielectric device with partially closed hole
US6765457B2 (en) 2001-05-30 2004-07-20 Murata Manufacturing Co., Ltd. Dielectric filter, dielectric duplexer, and communication device having elongated through holes
US20090146761A1 (en) 2007-12-10 2009-06-11 Nummerdor Jeffrey J RF monoblock filter with recessed top pattern and cavity providing improved attenuation

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6247201A (ja) * 1985-08-23 1987-02-28 Murata Mfg Co Ltd 誘電体共用器
JPS62104201A (ja) * 1985-10-30 1987-05-14 Fujitsu Ltd 誘電体フイルタ
JPH06237104A (ja) * 1993-01-11 1994-08-23 Matsushita Electric Ind Co Ltd フィルタ装置
JPH07176908A (ja) * 1993-12-16 1995-07-14 Murata Mfg Co Ltd 誘電体共振部品およびその特性調整方法

Patent Citations (43)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4673902A (en) 1983-11-25 1987-06-16 Murata Manufacturing Co., Ltd. Dielectric material coaxial resonator filter directly mountable on a circuit board
JPS614303A (ja) 1984-06-19 1986-01-10 Nec Corp 誘電体帯域通過フイルタ
JPS61258502A (ja) 1985-05-10 1986-11-15 Murata Mfg Co Ltd マイクロ波フイルタ
US4737746A (en) 1985-10-18 1988-04-12 Alps Electric Co., Ltd. Dielectric filter
US4837534A (en) 1988-01-29 1989-06-06 Motorola, Inc. Ceramic block filter with bidirectional tuning
US4937542A (en) 1988-11-16 1990-06-26 Alps Electric Co., Ltd. Dielectric filter
US5227747A (en) 1989-06-15 1993-07-13 Oki Electric Industry Co., Ltd. Dielectric filter having coupling amount adjusting patterns
US5079528A (en) 1989-06-21 1992-01-07 Murata Manufacturing Co. Ltd. Dielectric filter
US5144269A (en) 1990-03-20 1992-09-01 Sanyo Electric Co., Ltd. Dielectric filter having external connection formed on dielectric substrate
US5214398A (en) 1990-10-31 1993-05-25 Ube Industries, Ltd. Dielectric filter coupling structure having a compact terminal arrangement
JPH04242301A (ja) 1991-01-17 1992-08-31 Matsushita Electric Ind Co Ltd 誘電体フィルタ
US5345202A (en) 1991-03-25 1994-09-06 Sanyo Electric Co., Ltd. Dielectric filter comprising a plurality of coaxial resonators of different lengths all having the same resonant frequency
US5191305A (en) * 1991-07-02 1993-03-02 Interstate Electronics Corporation Multiple bandpass filter
US5177458A (en) 1991-07-31 1993-01-05 Motorola, Inc. Dielectric filter construction having notched mounting surface
JPH05167308A (ja) 1991-12-11 1993-07-02 Fuji Elelctrochem Co Ltd 誘電体フィルタ
US5208566A (en) 1992-01-21 1993-05-04 Motorola, Inc. Dielectric filter having adjacently-positioned resonators of dissimilar cross-sectional dimensions and notched side surface
JPH05275905A (ja) 1992-03-25 1993-10-22 Oki Electric Ind Co Ltd 分波器の実装構造
US5486799A (en) 1992-05-08 1996-01-23 Oki Electric Industry Co., Ltd. Strip line filter and duplexer filter using the same
US5572175A (en) 1992-09-07 1996-11-05 Murata Manufacturing Co., Ltd. Coaxial dielectric resonator apparatus having a plurality of side recesses located on a mount substrate
JPH06216607A (ja) 1993-01-18 1994-08-05 Ube Ind Ltd 誘電体フィルタ及びその製造方法
US5686873A (en) * 1993-11-18 1997-11-11 Murata Manufacturing Co., Ltd. Antenna duplexer having transmit and receive portion formed in a single dielectric block
US5563561A (en) 1994-02-17 1996-10-08 Murata Manufacturing Co., Ltd. Dielectric block apparatus having two opposing coaxial resonators separated by an electrode free region
US5512866A (en) 1994-04-29 1996-04-30 Motorola, Inc. Ceramic duplex filter
WO1995030250A1 (en) 1994-04-29 1995-11-09 Motorola Inc. An improved ceramic duplex filter
US5602518A (en) 1995-03-24 1997-02-11 Motorola, Inc. Ceramic filter with channeled features to control magnetic coupling
US5783978A (en) 1995-06-21 1998-07-21 Matsushita Electric Industrial Co., Ltd. Band rejection filter having a plurality of dielectric resonator with cutout portions having electrodes therein
US6023207A (en) 1996-02-09 2000-02-08 Ngk Spark Plug Co., Ltd. Dielectric filter and method for adjusting resonance frequency of the same
US5731751A (en) 1996-02-28 1998-03-24 Motorola Inc. Ceramic waveguide filter with stacked resonators having capacitive metallized receptacles
US5793267A (en) 1996-03-07 1998-08-11 Murata Manufacturing Co., Ltd. Dielectric block filter having first and second resonator arrays coupled together
US6052040A (en) 1997-03-03 2000-04-18 Ngk Spark Plug Co., Ltd. Dielectric duplexer with different capacitive coupling between antenna pad and transmitting and receiving sections
EP0865094A2 (de) 1997-03-14 1998-09-16 Taiyo Yuden Co., Ltd. Wellenfilter mit zwei oder mehr dielektrischen Koaxialresonatoren in Juxtaposition
US6236288B1 (en) 1997-03-31 2001-05-22 Murata Manufacturing Co., Ltd. Dielectric filter having at least one stepped resonator hole with a recessed or protruding portion, the stepped resonator hole extending from a mounting surface
US5959511A (en) 1998-04-02 1999-09-28 Cts Corporation Ceramic filter with recessed shield
US6204738B1 (en) 1998-04-17 2001-03-20 Murata Manufacturing Co., Ltd. Dielectric filter, dielectric duplexer, mounting structure thereof, and communication device
EP0951089A2 (de) 1998-04-17 1999-10-20 Murata Manufacturing Co., Ltd. Dielektrisches Filter, dielektrischer Duplexer, Montierungsstruktur und Kommunikationsvorrichtung
US6313797B1 (en) 1998-10-22 2001-11-06 Murata Manufacturing Co., Ltd. Dielectric antenna including filter, dielectric antenna including duplexer, and radio apparatus
US6498542B1 (en) 1999-02-03 2002-12-24 Murata Manufacturing Co., Ltd. Dielectric resonant device, dielectric filter, dielectric duplexer, communication apparatus including the same, and method for forming input-output electrode of the dielectric resonant device
US20010052832A1 (en) 1999-09-17 2001-12-20 Tdk Corporation Dielectric filter, and method of manufacturing the same
US20020109562A1 (en) 2001-02-15 2002-08-15 Murata Manufacturing Co., Ltd. Dielectric filter, dielectric duplexer, and communication device
US6765457B2 (en) 2001-05-30 2004-07-20 Murata Manufacturing Co., Ltd. Dielectric filter, dielectric duplexer, and communication device having elongated through holes
US6737943B2 (en) 2001-07-25 2004-05-18 Tdk Corporation Dielectric device with partially closed hole
US20030151468A1 (en) 2002-02-14 2003-08-14 Reddy Vangala Reduced length metallized ceramic duplexer
US20090146761A1 (en) 2007-12-10 2009-06-11 Nummerdor Jeffrey J RF monoblock filter with recessed top pattern and cavity providing improved attenuation

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130038404A1 (en) * 2010-01-07 2013-02-14 Jeffrey J. Nummerdor Duplex Filter with Recessed Top Pattern and Cavity
US9030272B2 (en) * 2010-01-07 2015-05-12 Cts Corporation Duplex filter with recessed top pattern and cavity
RU2636404C2 (ru) * 2016-02-24 2017-11-23 Акционерное Общество "Специальное Конструкторско-Технологическое Бюро По Релейной Технике" (Ао "Сктб Рт") Двухполосный керамический фильтр
US10333191B2 (en) 2016-09-23 2019-06-25 Cts Corporation Ceramic block RF filter having a first plurality of through-hole resonators and a second plurality of through-holes for blocking RF signal coupling
US11433468B2 (en) 2016-09-30 2022-09-06 General Electric Company Electrode for an electro-erosion process and an associated method thereof
US10587024B2 (en) 2016-10-21 2020-03-10 LGS Innovations LLC Hermetic sealing of ceramic filters
US10587025B2 (en) 2016-11-08 2020-03-10 LGS Innovations LLC Ceramic filter with window coupling

Also Published As

Publication number Publication date
KR20110102925A (ko) 2011-09-19
JP2012514954A (ja) 2012-06-28
WO2010080929A1 (en) 2010-07-15
CN202839908U (zh) 2013-03-27
DE112010000694T5 (de) 2012-11-08
GB201113470D0 (en) 2011-09-21
US20100141352A1 (en) 2010-06-10
CN202308233U (zh) 2012-07-04
CA2749145A1 (en) 2010-07-15
GB2479108A (en) 2011-09-28

Similar Documents

Publication Publication Date Title
US8261714B2 (en) RF monoblock filter with outwardly extending wall to define a cavity surrounding a top surface of the filter
US8294532B2 (en) Duplex filter comprised of dielectric cores having at least one wall extending above a top surface thereof for isolating through hole resonators
US9030275B2 (en) RF monoblock filter with recessed top pattern and cavity providing improved attenuation
EP1742354B1 (de) Mehrlagiges Bandpassfilter
US7541893B2 (en) Ceramic RF filter and duplexer having improved third harmonic response
US9030272B2 (en) Duplex filter with recessed top pattern and cavity
US10587025B2 (en) Ceramic filter with window coupling
US7321278B2 (en) Low profile ceramic RF filter including trap resonators and a decoupler
US9030276B2 (en) RF monoblock filter with a dielectric core and with a second filter disposed in a side surface of the dielectric core
US6650202B2 (en) Ceramic RF filter having improved third harmonic response
US6677836B2 (en) Dielectric filter device having conductive strip removed for improved filter characteristics
US8269579B2 (en) RF monoblock filter having an outwardly extending wall for mounting a lid filter thereon
CA2733854C (en) Rf monoblock filter assembly with lid filter
US20060164182A1 (en) Surface acoustic wave filter
JP2006253836A (ja) 誘電体フィルタならびにそれを用いたアンテナ共用器および通信装置

Legal Events

Date Code Title Description
AS Assignment

Owner name: CTS CORPORATION, INDIANA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:NUMMERDOR, JEFFREY J.;REEL/FRAME:024916/0571

Effective date: 20100302

STCF Information on status: patent grant

Free format text: PATENTED CASE

FPAY Fee payment

Year of fee payment: 4

MAFP Maintenance fee payment

Free format text: PAYMENT OF MAINTENANCE FEE, 8TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1552); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Year of fee payment: 8

MAFP Maintenance fee payment

Free format text: PAYMENT OF MAINTENANCE FEE, 12TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1553); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Year of fee payment: 12